The expression “controller” is used herein to denote a device configured to generate control signals for controlling a remotely located device (a “target”). Typically, the controller and target are connected by a wire pair or electrically conductive cable which terminates at an infrared (IR) emitter positioned near the target (or, in some cases, by a cable including an optical fiber or bundle of optical fibers), and the control signals propagate from the controller to the target (or to an IR emitter positioned near the target) over the wire pair or cable. For example, electrical control signals propagate over a wire pair from the controller to an IR emitter positioned near the target and IR control signals generated in the IR emitter in response to the electrical control signals propagate to the target. Alternatively, the controller and target are not connected by any wire pair or cable, and the control signals are transmitted (typically as electromagnetic radiation) from controller to target.
The expression “wall-mounted” device herein denotes a device that is mounted on or to a wall (e.g., in an electrical box affixed to a wall) or other object that is fixed during use of the device (e.g., a podium) and is designed to remain so mounted when in use. The expression “wall-mountable” device herein denotes a device that can be mounted on or to a wall or other object (e.g., a podium) that is to remain fixed during use of the device, and is designed to remain so mounted when in use.
Many types of handheld and wall-mounted controllers have been employed to control projectors, audio and video devices, and other devices. Typically, controllers have a large number of control keys (which are often quite small) and thus require that the user devote significant effort and attention to operating them. Some conventional controllers can be programmed (e.g., are operable in a learning mode in which they can be programmed) to execute specific programmed operations in response to user actuation of specific ones of their keys. However, a user must devote significant effort and attention to operating a conventional programmed controller of the type having a large number of keys from which the user must select.
Controllers having a small number of keys (e.g., less than eight keys) can be operated with less effort and attention from a user than controllers having more keys, since the user can more easily identify (and remember the location of) a desired key that belongs to a small set of keys than a desired key that belongs to a large set of keys. It is also desirable to reduce the number of control keys of a controller to reduce manufacturing cost. A programmable controller having a small number of control keys can be less expensive to manufacture than a nonprogrammable (or programmable) controller having a greater number of control keys.
However, a user must also devote significant effort and attention to operating conventional, wall-mounted, programmable controllers that have a small number of control keys. This is true for the following reasons. On such a controller, the programmed key for executing any specific operation can be located anywhere. Since the controller's face is not partitioned into regions allocated to control functions of specific, predetermined types, the user must learn (e.g., by inspecting a label) the control operation that each key has been programmed to execute. Typically, the keys of a conventional, wall-mounted, programmable controller are labeled after the controller is programmed to indicate to the user the control operation associated with each programmed key. Even with the keys so labeled, a user typically must study all or a large part of the controller's face to locate a desired key because the key could be located anywhere on the face.
There is a need for a programmable, wall-mounted controller having a small number of keys (i.e., less than eight keys), and which can be operated by a user with less effort and attention than required for operation of conventional, programmable, controllers.